Along with Ahmadinejad's aide, Esfandiar Rahim Mashaei, the name of former President Akbar Hashemi Rafsanjani was also notably absent from the list of approved nominees, as was that of former Foreign Minister Manouchehr Mottaki.

The vetting process was carried out by Iran's Guardian Council, the country's most influential clerical body, which operates under the watchful eyes of Supreme Leader Seyed Ali Khamenei.

Iran's candidate, and nuclear negotiator

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Uncertainty in Iranian elections

Ahmadinejad appealed for his supporters to be patient Wednesday, saying on his website that he would seek help from Khamenei.

Ahmedinejad said "the rights of the oppressed will not be trampled on in a country where there exists a supreme religious leader," referring to Khamenei, and insisted that he expected the issue to "be resolved."

Ahmadinejad, who is term-limited and so cannot run for a third consecutive term, has been grooming Mashaei to take over for years.

The head of Rafsanjani's election campaign office said the former president will not object to the Guardian Council's decision, Press TV reported.

The eight approved nominees, whose names were released by Iran's Interior Ministry late Tuesday, are:

-- Gholam-Ali Haddad-Adel, a former Parliament speaker whose daughter is married to Khamenei's son;

-- Ali Akbar Velayati, twice foreign minister during the Rafsanjani presidency and currently the supreme leader's top adviser.

Among the approved nominees, only Gharazi, Aref and Rouhani are not known to be devout followers of Khamenei.

The run-up to the elections has been characterized by factionalism and political infighting, observers say.

Four years ago, Ahmadinejad's reelection sparked mass protests amid claims of electoral fraud. His chief rival, reformist Mir Hossein Moussavi, became a leader of the opposition Green Movement along with Mehdi Karrubi. The two subsequently were placed under house arrest, where they remain.

Rafsanjani's last-minute registration on Saturday had the potential to change the face of the election.

Rafsanjani, who served two terms as president from 1989 to 1997, has long been a staunch critic and bitter political rival of Ahmadinejad.

Weeks after the 2009 elections, Rafsanjani condemned the regime's violent crackdown against the opposition movement and spoke out for the people's right to peacefully protest. He later toned down the attacks and made statements of apparent support of the regime and Khamenei.

He is widely believed to be one of the wealthiest and most politically powerful men in Iran.

A government news website cited the Interior Ministry's elections chief, Seyed Solat Mortazavi, as saying official campaigning would begin on Friday and last for 20 days, ending June 12.

Voters also will elect members of city and rural Islamic councils on June 14.

Iran's semiofficial Fars news agency said the eight presidential candidates would collectively have 539 hours of free TV and radio time to outline their plans.